A defense contractor and former U.S. Army officer has been charged with communicating national defense secrets to a 27-year-old Chinese national with whom he had a romantic relationship.

According to a criminal complaint unsealed in federal court Monday in Hawaii, Benjamin Pierce Bishop, 59, who held a top secret clearance, transmitted "national defense information regarding existing war plans, information regarding nuclear weapons, and relations with international partners," to an email address known to be used by the woman referred to as "Person 1."

Bishop met the woman during a conference on international military defense issues and according to the complaint, she "may have been at the conference in order to target individuals such as Bishop," who work with and have access to classified information.

Court records state that Bishop maintained "an intimate, romantic relationship with Person 1 since June 2011," and worked to hide that relationship from the U.S. government. Bishop was required to report foreign contacts as part of maintaining his security clearance.

According to the complaint, investigators learned through court authorized wiretaps that Bishop was discussing "national defense information, regarding planned deployments of U.S. strategic nuclear systems, as well as the ability of the U.S. to detect low and medium range ballistic missiles of foreign governments to Person 1."

The information, the complaint alleges, could cause "serious damage to U.S. national security." Bishop also allegedly discussed information "regarding the deployment of U.S. early warning radar systems in the Pacific Rim and the ability of the U.S. to detect short range and medium range ballistic missiles of foreign governments," as well as the proposed deployment of a U.S. radar system in the Pacific.

A search of Bishop's Hawaiian home uncovered additional secret documents including one titled, "Fiscal Year 2014-2018 Defense Planning Guidance." The document is described as the "definitive planning document for force development." Bishop was not authorized to possess these documents in his home.

In February, the complaint alleges, Person 1 "tasked" Bishop to conduct research on what western nations know about a particular Chinese naval asset. The information was outside the scope of Bishop's regular work assignments and investigators recovered classified documents related to the information Person 1 requested in his work space.

Person 1 remains in the United States had has not been charged at this point, according to a source familiar with the investigation. The nature of the information allegedly passed to a Chinese national in the U.S. on a J-1 student visa raises serious concerns about the data having been passed to a foreign government and remains a focus of the ongoing investigation.

A court appointed attorney for Bishop, Birney Bervar, briefly defended his client before reporters Monday.

"Col. Bishop has served this country for 29 years. He would never do anything to harm the United States," he said.